Lincoln's embalmment

[Eva Elisabeth]

I wonder why RFK bled profusely at once and AL formed a clot and did not?

My humble guess: because in RFK's case the bullet entered close(r ) to the ear and smashed the arteria carotis externa, interna, or both (thus the main arteriae):
   
...while in A. L.'s case the bullet entered farther back and affected only smaller arteries - see the drawing Roger posted here: http://rogerjnorton.com/LincolnDiscussio...-1114.html